Monoazo dye for wool.



- NoDfa'wingf To all whom it may concern."

Be it known that we, Wirinemr Hnnznnno and Osnzua; Sonanmxnano, citizens of the German Empire, residing at and whose postoiiice addresses are, respectively, Landshuterstrasse 2i and iVartburgstrasse S, Schiineberg, near Berlin. Germany, have inventecha lowing formula Xewhionoazo Dye for Wool, of which the following is a specification.

Our present invention relates to a "new monoazo-dye'ior wool andespecially adapted to a subsequent treatment with oxidizing chromium compounds, which can be obtained by diazotizing the urea dern'ative of the folwhich derivative may be obtained for instance byac-t-ing with phosgen: COCl upon Lat-amidophenol-Q-nitro 6-su1fonio acid and reducing the condensation product,' and co1n-.

bining the resulting tetrazo compound with beta-naphthol. The dye thus obtained produces on wool from an-acid bath brownish red tints which by a subsequent treatment with potassium bichromate change to a black violetpossessing a great fastness to milling J and potting besides an excellent f astness against the action-of light.

The following example serves to illustrate our invention the parts'being by weight: 43.5 parts of the urea derivative of the above-given formula are tetrazotized in the usual manner by means of hydrochloric acid and sodium' nitrite. The tetrazo solution thus obtained is allowed to run while stirrin into a. solution of 29 parts of 'beta-naphtho 3 containing illO-CfilCllliliQCl proportion of canstic soda lye and such a quantityof sodium carbonate as to guarantee all rline reaction throughout the whole combination. The reiaction being finished the mass is --warmed up, whereupon the dye is precipitated-by the addition of common salt and isolated in the usual manner. i

noaoaze in; fo'aiwo "Specifidatioii otiettei slatent;

Applicationwfiled ilovemiieif 1 4. ISIQSerial-iici 1 Tli e new-i product. dyes. wool.:from' an acid bathbrownish zred tints which on subsequent;

treatment with potassium bichromate change 4 to black-violet. The new dye in'the dry state when pulverized forms a dark pow dert having abronze-like luster; 1t dissolves in;

water to a. violet solution which on the addi-- tion of' concentrated soda-lye turns to a claret color, the dye-being separatedto a great deal in claret flakes, and on the addi- -tion of concentrated hydrochloric acid separates a "brownprecipitate; ,concentratedliquor ammonia changes tlie color o f:the

aqueous solution to claret. The new product is insoluble in alcohol; it dissolves in concentrated sulfuric acid toa red violet solu;

tion which solution on t-he addition 'ot ice shows a brown precipitate. By the action of strong reducingagents, such as forin; stance sta-nnous' chlorld and hydrochloric acid, the new coloring matter 1s split up, the

urea derivative which serves as parent ma-- terial for the production of the dyerbeing regenerated .and 1-amido-2-naphtho1 being simultaneously formed.

It is obvious that our present invention is not limited to the foregoing example or to the details given therein.

Haying now described our invention and the manner m'wlnch 1t may be carried out' As a new article of manufacture the new monoazo dye for wool, which may be ob-.

- i NH:

and combining the tetrazocompound thus obtained w th beta haphthol, which new dye in the shape Jofthe sodium salt in the dry state when pulverized forms a dark powder having a bronze-like luster and dissolves in water to a violet solution which solution on. the addition ofconcentrated soda-lye assumes' a claret color, the dye being separated M a great deal inclaret flakes and on the -,'addition-of concentrated hydrochloric acid separates a brown precipitate and on the addition of concentrated liquor ammoniagturns to a claret solution and this new dyebeing ing matter by the action ofstrong reducing agents', stannous chlorid and hydrochloric acid, is split up, theurea derivative'which serves as parent material for the reduction of the dye being regenerated an l-amido- Z-naphthol being simultaneously formed,

which ncw'dye produces on wool from an acid bath brownish-red tints which on subsequent treatment withpotassium bichroma'te change to a black-violet which is very fast to milling and potting and possesses an elx cellenffastncss against the action of light; In testimony whereof we have hereunto set our hands 1n presence of two subscrlbmg witnesses. a I

WILI-IELM HERZBERG..

OSWALD SCHARFENBERG:

\Vitnesses-r HENRY HASPER, 'VVOLDEMAR HAUPT. 

